1. Technical Field
The present disclosure relates to a gesture recognition system and a method thereof, in particular, to a gesture recognition system and a method thereof capable of recognizing a natural gesture by using a parallel gesture template matching manner, and realizing marker-less and real-time gesture recognition.
2. Related Art
Gesture detection is widely applied. However, for marker-less gesture detection, especially when a template matching technology is employed, the position and posture of a hand must be resolved, which generally requires a large amount of operation performance, and is thus difficult to achieve the application requirement of real-time recognition.
In the technology disclosed in the published U.S. Pat. No. 6,128,003, a moving image object is found out in an image, and it is assumed that the only moving object in the image is a gesture. First of all, gesture templates at all angles are established, and rotational vectors are resolved for all the templates. Then, a shape and a rotational vector of the moving object are resolved from the captured read-time image, and are matched with the rotational vectors of the established templates one by one, so as to find out the most resembling template. In addition, in order to accelerate the speed of distinguishing the image object, the rotational vectors of the templates are respectively analyzed and classified into hierarchical data structures in accordance with their characteristics, so as to avoid matching all the data in a template database each time, thereby achieving the effect of real-time recognition.
In the published U.S. Pat. No. 6,256,033, it is highlighted that a gesture recognition method disclosed therein achieves the effect of real-time recognition. In the method, a motion object is measured and then fetched to be matched with template data in a previously established template database, so as to achieve the effect of real-time recognition.
In both of the above two known techniques, it is assumed that the moving object in the image is a hand position, and the reason is that, for template matching, the complexity of a background tends to affect the result of the template matching. Therefore, in order to quickly separate the background and the foreground, and perform the template matching for hand more correctly without the background interference, the hand must be assumed as a moving object.
Besides the methods of matching with templates, other methods of gesture tracking based on color are also provided. For example, in the published U.S. Pat. No. 6,788,809, an object in an image is defined by color segmentation and gesture recognition. First, a color in the image corresponding to that of the object is selected from the image. Then, depths for all image grids in the image are set on a stereo camera, and the image grids corresponding to undesired depth values are eliminated, thereby achieving the effect of background subtraction. After that, an already established gesture template database is employed to be matched with the image, so as to know about messages about the gestures. In this method, two cameras are used for calculating the distances and depths of all the grids in the image, and a scope of the hand is defined with the known distance and depth of the hand, such that the background is removed before the template matching. However, a depth critical point to be resolved must be controlled, beyond which the hand is considered as the background and cannot be resolved.
In the published U.S. Pat. No. 7,050,606, colors are used for detecting an object such as a hand or body, and assisting detection with motion tracking, so as to achieve a more accurate and rapid effect. This technology assists detection through motion tracing, thereby accelerating the operation speed of an image.